Metallocene catalyst systems are well known in the art. While the prior art discloses the use of olefins to prepare prepolymer and the use of polyolefins as supports, the prior art does not disclose the use of olefins as a reactant with the metallocene active site to promote catalyst system activity. For example, U.S. Pat. No. 5,346,925 describes supporting catalyst components on porous polymer supports such as polystyrenes. Canadian Patent Application No. 2,093,056 also describes using polymeric supports such as polystyrenes. WO 96/34020 describes a catalyst system prepared with an inert hydrocarbon and WO 95/25129 describes a method for preparing catalyst systems using a spray drying technique which can include polystyrene microparticles. EP 748823 A1 describes the use of styrene and styrenic compounds combined with certain transition metal compounds and modified alumoxanes to prepare catalyst systems.
The present inventor has discovered that the activity of metallocene catalyst systems is substantially increased when certain olefin promoters are used to prepare the catalyst systems.